System and method for foundations for roadside signs and structures

ABSTRACT

A ground screw anchor foundation for a roadside sign comprises at least one elongated soil screw defining a longitudinal axis. The soil screw includes a barrel section having an upper end and a lower end and a substantially circular cross-section of a first diameter. A point section is connected to the lower end, the point section tapering from a second diameter at a position along the longitudinal axis proximate to the barrel section to a third diameter at a position along the longitudinal axis distal to the barrel section. A helical thread is disposed on an outer surface of at least a portion of the point section. A first component of a breakaway system is mounted on the upper end of the barrel section of the soil screw. The first component is adapted for releasable connection in a breakaway manner to a second component on a roadside sign.

TECHNICAL FIELD

The following disclosure relates to systems for providing foundationsfor roadside signs, in particular for providing foundations including aground screw and an integral slip base, such that the foundation can beinstalled in the ground without excavation, can be removed intact fromthe ground after use and/or can be reused in another location afterremoval.

BACKGROUND

Roadside safety is a controlling element within the roadway signingindustry. The most widely accepted safety element for small roadsidesigns is a breakaway system. The Federal Highway Administration,numerous universities, private inventors, and numerous state Departmentsof Transportation have crash-tested numerous types of breakaway systemsin the past 30 years. There are several breakaway systems approved foruse on our national highway system. One of the commonly used breakawaysystems is commonly known as the “triangular slip base.” U.S. Pat. No.4,926,592 to Nehls describes a breakaway sign post coupling comprising atriangular slip base. The entire disclosure of U.S. Pat. No. 4,926,592is incorporated herein by reference.

Conventionally, a foundation for a roadside sign includes a triangularslip base anchored to the ground with a 12″ diameter×42″ deep drilledshaft concrete foundation. As the name implies, the drilled shaftconcrete foundation involves drilling a hole in the ground at thedesired location and filling it with concrete. The slip base stub ismounted in the wet concrete before it sets up. This is a “one size fitsall” roadside sign foundation that is used in every soil type.

Though widely used, there are several disadvantages to the conventionaldrilled shaft concrete foundation for roadside signs. One disadvantageis the amount of man hours and physical labor required for a completesign installation. The typical installation of a sign with a drilledconcrete foundation takes two trips by a work crew: one trip to drilland pour the foundation; and a second trip, no sooner than four dayslater, to install the sign after the concrete has cured. Also, theamount of equipment and physical labor to install the foundation isfairly exhaustive. For example, to install a typical 12″ dia.×42″ deepdrilled shaft foundation requires a drilling truck and operator, atrailer or separate truck to haul water, dry concrete mix that willresult in a 3,000 psi concrete, a wheel barrel, concrete mixing tools,hand tools to load or spread the spoils from drilling the shaft, andcones/barricades to keep vehicles or pedestrians away from the curingfoundation and slip base stub extrusion. In all, the installation of adrilled shaft foundation is labor extensive and exhaustive. A needtherefore exists, for an improved foundation system for installation ofroadside signs that is more efficient of labor and materials.

Of course, if commercially-mixed (i.e., mixing truck delivered) concreteis used, no hand mixing or lifting is required, except possibly forhauling the concrete by wheel barrel if the foundation location cannotbe reached with the concrete chute. However, commercial concretesuppliers typically cannot accurately batch less than a half a truckload of concrete, and typically have a minimum charge for delivery. Thususing commercially-mixed concrete can be extremely expensive when only afew signs are installed at time. A need therefore exists, for animproved foundation system for installation of roadside signs that iseconomical to use when installing only one sign or only a few signs.

Further, there are numerous locations along almost any roadway thatrequire sign placements in location that are extremely difficult andcostly to access with a drilling truck and hand- or commercially-mixedconcrete. These locations include steep side slopes and areasprotected/separated from the roadway by metal beam guard fence orconcrete barrier. These locations can normally be easily accessed byfoot but not by large trucks and drilling equipment. A need thereforeexists, for an improved foundation system for installation of roadsidesigns that does not require access by large trucks and drillingequipment.

Another disadvantage of the conventional drilled shaft concretefoundation for roadside sign use is that, once in place, suchfoundations cannot be moved or reused. Thus, removing a sign installedwith such a foundation requires either: pulling up the entirefoundation, back-filling the void, and disposal of a 400 pound chunk ofconcrete; or breaking the existing foundation back to 2′ below theexisting ground elevation, removal and disposal of 225 pounds ofconcrete rubble, and then backfilling the void. Moving the sign requiresinstallation of a new concrete foundation at the new location, inaddition to the foundation removal process just described. A needtherefore exists, for an improved foundation system for installation ofroadside signs that allows removal and/or reuse of the foundation.

SUMMARY

In one aspect thereof, the invention comprises a foundation system thatcan be used for both permanent and temporary roadside sign installation.The foundation is reusable and meets national safety requirements. Ascompared to conventional concrete sign foundation systems, thisfoundation requires less manpower to install, expends less nonrenewableresources to install, is adaptable to all soil types, can be installedin hard to reach locations more easily, does not generate earthenspoils, and allows sign installation up to 350 times faster thanconventional foundations.

In another aspect thereof, the invention comprises a ground screw anchorfoundation including an anchor plate of a breakaway system and a soilscrew foundation. In preferred embodiments, the soil screw is steel.Embodiments of this ground screw anchor foundation can be screwed intoand out of the ground with equal ease, and thus are totally reusable;unlike conventional concrete foundations. Embodiments of this groundscrew anchor foundation can be installed in any soil type. Embodimentsof this ground screw anchor foundation can be installed and ready forsign placement in less than 15 minutes, compared to the 96 hours for asign placed on a concrete foundation (including cure time for theconcrete), i.e., over 350 times faster than concrete foundations.

In other aspects thereof, the invention comprises an installation deviceand installation methods that require only one piece of installationequipment to install a foundation for the roadside sign. Variousembodiments of the installation device are a hand-held, truck-mountableand/or mountable on a compact utility vehicle (UTV) (e.g., “Bobcat”utility vehicle). Various embodiments of the installation device arehydraulic powered and/or electric powered. The UTV-mountableinstallation device and/or the hand-held installation device allow foreasy access to those hard to access locations, cutting down on the needfor specialized equipment and the expense to access these locations withlarge cumbersome drilling equipment needed for drilled shaftfoundations.

In still further aspects, the invention includes methods for installingfoundations for roadside signs that do not require any heavy, exhaustivelifting and/or concrete mixing as required for the conventional concretefoundations. Embodiments of the invention require only the lifting of aground screw anchor foundation that weighs, on average, within the rangefrom 18 to 21 pounds (as compared to five, 80 pound bags of concrete and30 pounds of water that must be loaded, unloaded, and mixed for everydrilled shaft).

In another aspect thereof, the invention comprises systems forinstalling a roadside sign that do not produce earthen spoils like adrilled shaft foundation. Embodiments of the ground screw anchorfoundation do not displace soil upward. Instead, as the screw portion ofthe ground screw anchor foundation is pulled into the soil by the screwthreads, the surrounding soil is displaced outward (not upward), therebycompacting/densifying the surrounding soil. Since there are no spoilslike a concrete foundation, there is not 350 pounds of earthen spoils tohaul away or spread around every foundation location. Such embodimentsmay save time, money, and labor effort compared to using a conventionalconcrete foundation.

In still another aspect thereof, the invention comprises a foundationsystem that is conservative of natural- and nonrenewable-resources andis 100% recyclable. Whereas; no part of a conventional concrete shaftfoundation can be economically recycled, embodiments of the inventionmay be formed from steel (a recyclable material). Preferred embodimentsmay be formed from recycled steel. Further embodiments conserveresources since a sign crew and equipment are only required to travel toa foundation site one time (instead of twice) to complete installationof a sign foundation and sign. Thus, with respect to the expenditure ofnonrenewable fuel resources, installation in accordance with theseembodiments is twice as efficient as the installation of a conventionalconcrete foundation.

In yet another aspect thereof, a ground screw anchor foundation for aroadside sign comprises at least one elongated soil screw defining alongitudinal axis. Each soil screw includes a barrel section having anupper end and a lower end defining a first length therebetween, and asubstantially circular cross-section of a first diameter, viewed alongthe longitudinal axis. Each soil screw further includes a point sectionconnected to the lower end of the barrel section, the point sectiontapering from a second diameter at a position along the longitudinalaxis proximate to the barrel section to a third diameter at a positionalong the longitudinal axis distal to the barrel section. A helicalthread is disposed around the longitudinal axis on an outer surface ofat least a portion of the point section. The ground screw anchorfoundation further comprises a first component of a breakaway system ismounted on the upper end of the barrel section of the soil screw.

In another embodiment, the first component of the breakaway systemfurther comprises a plate member having a substantially planar uppersurface. The plate member is mounted on the upper end of the barrelsection such that the plane of the upper surface forms an angle with thelongitudinal axis, the angle being within the range from 60° to 90°.

In another embodiment, the plate member of the first component of thebreakaway system includes three lateral sides depending from the uppersurface, the lateral sides being configured in the form of anequilateral triangle; and each lateral side being configured toterminate before reaching an apex with an adjacent lateral side, therebydefining a notch at each point of intersection.

In yet another embodiment, the ground screw anchor foundation furthercomprises a second soil screw disposed in a spaced-apart relation to thefirst soil screw, the longitudinal axis of the second soil screw beingsubstantially parallel to the longitudinal axis of the first soil screw.The first component of the breakaway system includes a channel membermounted to the respective upper ends of the barrel sections of the firstand second soil screws and a plate member having a substantially planarupper surface mounted on the beam such that the plane of the uppersurface of the plate member forms an angle with the longitudinal axes ofthe soil screws, the angle being within the range from 60° to 90°.

In still another embodiment, the plate member of the first component ofthe breakaway system includes three lateral sides depending from theupper surface, the lateral sides being configured in the form of anequilateral triangle; and each lateral side being configured toterminate before reaching an apex with an adjacent lateral side, therebydefining a notch at each point of intersection.

In yet another aspect thereof, a method is provided for installing aground screw anchor foundation for a roadside sign in a soil substrate,the foundation being adapted for supporting a roadside sign including asecond component of a breakaway system, a sign post attached to an upperside of the second component, and a sign attached to the sign post. Themethod comprises the following steps: 1) providing a first elongatedsoil screw; 2) providing a first component of a breakaway system, thefirst component being cooperatively engageable in a breakaway manner toa second component of a breakaway system adapted for attachment to aroadside sign; 3) connecting the first component of the breakaway systemto the upper end of the barrel section of the first soil screw; 4)releasably connecting a torque-supplying device to the first soil screw;5) positioning the first soil screw such that the point section isdisposed on a surface of a soil substrate and the longitudinal axis isoriented substantially perpendicular to the surface of the soilsubstrate; 6) rotating the first soil screw about its longitudinal axiswith the torque supplying device until the helical thread on the pointsection engages the soil substrate and draws the point section apredetermined distance into the soil substrate; and 7) disconnecting thetorque-supplying device from the first soil screw.

In another embodiment, the first component of the breakaway systemfurther comprises a plate member mounted on the upper end of the barrelsection of the soil screw, the plate member having a substantiallyplanar upper surface, three lateral sides depending from the uppersurface, the lateral sides being configured in the form of anequilateral triangle; and each lateral side being configured toterminate before reaching an apex with an adjacent lateral side, therebydefining a notch at each point of intersection.

In another embodiment, the first component of the breakaway system isconnected to the soil screw before the soil screw is releasablyconnected to the torque-supplying device; and the torque-supplyingdevice includes an adapter, the adapter being configured to releasablyconnect to the first component of the breakaway mounting member suchthat torque from the torque-supplying device is transmitted through theadapter and through the first breakaway mounting member to rotate thesoil screw around its longitudinal axis and into the soil.

In yet another embodiment, the torque-supplying device comprises anelectric motor operatively connected to the soil screw for rotating thesoil screw around its longitudinal axis.

In yet another embodiment, the torque-supplying device comprises ahydraulic motor operatively connected to the soil screw for rotating thesoil screw around its longitudinal axis.

In still another embodiment, the torque-supplying device comprises aninternal combustion engine operatively connected to the soil screw forrotating the soil screw around its longitudinal axis.

In a still further embodiment, the method further comprises thefollowing steps: a) providing a second elongated soil screw; b)releasably connecting a torque-supplying device to the second soilscrew; c) positioning the second soil screw such that the point sectionis disposed on the surface of the soil substrate and the longitudinalaxis is oriented substantially perpendicular to the surface of the soilsubstrate; d) rotating the second soil screw about its longitudinal axiswith the torque supplying device until the helical thread on the pointsection engages the soil substrate and draws the point section apredetermined distance into the soil substrate; e) disconnecting thetorque-supplying device from the second soil screw; and attaching thefirst component of the breakaway system to the respective upper ends ofthe first and second soil screws

In another embodiment, the first component of the breakaway systemfurther comprises a channel member connected to the respective upperends of the first and second soil screws and a plate member mounted onthe channel member. The plate member has a substantially planar uppersurface and three lateral sides depending from the upper surface. Thelateral sides are configured in the form of an equilateral triangle; andeach lateral side is configured to terminate before reaching an apexwith an adjacent lateral side, thereby defining a notch at each point ofintersection.

In still another embodiment, the first component of the breakaway systemfurther comprises a channel member connected to the respective upperends of the first and second soil screws and a plate member mounted onthe channel member. The plate member has a substantially planar uppersurface and is mounted on the beam such that the plane of the uppersurface of the plate member forms an angle with the longitudinal axes ofthe soil screws, the angle being within the range from 60° to 90°.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding, reference is now made to thefollowing description taken in conjunction with the accompanyingDrawings in which:

FIGS. 1 a, 1 b and 1 c show a ground screw anchor foundation inaccordance with a first embodiment having a triangular plate member,wherein FIG. 1 a is a perspective view, FIG. 1 b is a top view, and FIG.1 c is a side view;

FIG. 1 d shows an alternative embodiment having a square plate member;

FIG. 1 e shows an alternative embodiment having a rectangular platemember;

FIG. 2 shows a roadside sign mounted on the ground screw anchorfoundation of FIGS. 1 a, 1 b and 1 c;

FIG. 3 shows an enlarged partial view of a roadside sign assembly;

FIG. 4 shows a ground screw anchor foundation in accordance with anotherembodiment having multiple ground screw anchors and a triangular platemember;

FIGS. 5 a, 5 b, 5 c and 5 d show additional views of the first componentof a breakaway system for the ground screw anchor foundation of FIG. 4,wherein FIG. 5 a is a perspective view, FIG. 5 b is a top view, and FIG.5 c is an end view (i.e., viewed in the direction of line 408) and FIG.5 d is a side view;

FIG. 5 e shows an alternative embodiment having a square plate member;

FIG. 5 f shows an alternative embodiment having a rectangular platemember;

FIG. 6 shows a roadside sign mounted on the ground screw anchorfoundation of FIG. 4; and

FIG. 7 shows installation of a ground screw anchor using atorque-supplying device and an adapter in accordance with anotherembodiment.

DETAILED DESCRIPTION

Referring now to FIGS. 1 a, 1 b, and 1 c, there is illustrated a groundscrew anchor foundation for a roadside sign in accordance with oneembodiment. The ground screw anchor foundation 100 of this embodimentcomprises an elongated soil screw 102 defining a longitudinal axis 104.The soil screw 102 includes a barrel section 106 having an upper end 108and a lower end 110 defining a first length (denoted L₁) therebetween.The barrel section 106 has a substantially circular cross-section of afirst diameter (denoted D₁) when viewed along the longitudinal axis 104.In some embodiments, the diameter D₁ of the barrel section 106 is withinthe range from 3.0 inches to 4.0 inches. In preferred embodiments, thediameter D₁ is within the range from 3.25 inches to 3.75 inches. In someembodiments, the diameter D₁ of the barrel section 106 is about 3.5inches.

A point section 112 is connected to the lower end 110 of the barrelsection 106. The point section has an upper end 113 and a lower end 115defining a second length (denoted L₂) therebetween. The point section112 tapers from a second diameter (denoted D₂) at a position along thelongitudinal axis 104 proximate to the barrel section 106 to a thirddiameter (denoted D₃) at a position along the longitudinal axis distalto the barrel section. In the illustrated embodiment, the taper of thepoint section 112 is a single, constant angle (i.e., conic taper);however, in other embodiments the taper of the point section may includetwo or more angles (i.e., bi-conic or multi-conic taper) or may changecontinuously (e.g., secant- or elliptical-ogive taper).

A helical thread 114 is disposed around the longitudinal axis 104 on anouter surface of at least a portion of the point section 112. In someembodiments the thread 114 is disposed entirely on the point section112, while in other embodiments the helical thread may be disposed onportions of the barrel section 106 and the point section 112. A firstcomponent 116 of a breakaway system mounted on the upper end 108 of thebarrel section 106 of the soil screw 102.

As best seen in FIG. 1 c, in some embodiments, the first component 116of the breakaway system may further comprise a plate member 118 having asubstantially planar upper surface 120. The plate member 118 is mountedon the upper end 108 of the barrel section 106 such that the plane 122of the upper surface 120 forms an angle (denoted A₁) with thelongitudinal axis 104, the angle being within the range from 60° to 90°.Preferably, the plane 122 of the upper surface 120 forms an angle θ₁with the longitudinal axis 104 within the range from 80° to 90°. In someembodiments, the upper surface 120 of the plate member 118 will behorizontal after installation of the foundation 100.

As best seen in FIG. 1 b, in some embodiments, the plate member 118 ofthe first component 116 of the breakaway system includes three lateralsides 124 depending from the upper surface 120. The lateral sides 124may be configured in the form of an equilateral triangle; with eachlateral side being configured to terminate before reaching an apex 126with an adjacent lateral side, thereby defining a notch 128 at eachpoint of intersection (of the lines extending from the lateral sides).In other embodiments, the plate member 118 may be configured as anon-equilateral triangle.

Referring now also to FIGS. 1 d and 1 e, in still other embodiments, theplate member 118 may be configured with its upper surface 120 in theshape of a square, a rectangle or yet another different shape. FIG. 1 dillustrates an embodiment of a first component 116 having a plate member118′ configured in a square shape. FIG. 1 e illustrates an embodiment ofa first component 116 having a plate member 118″ configured in arectangular shape. Whether configured as a triangle, a square, arectangle or other shape, the plate member 118 of some embodiments mayinclude notches 128 formed at each point of intersection of the lateralsides (i.e., at the “corners” of the plate member), whereas the platemembers of other embodiments may not include notches.

Referring now to FIG. 2, there is illustrated a roadside sign assemblyin accordance with another embodiment. The roadside sign assembly 200includes a roadside sign 202 mounted on the upper end 204 of a sign post206. A ground screw anchor foundation as disclosed herein is connectedto the lower end 208 of the sign post 206. In the embodiment illustratedin FIG. 2, the ground screw anchor foundation is a foundation 100substantially identical to the foundation described in connection withFIGS. 1 a, 1 b and 1 c, however, other ground screw anchor foundationsas disclosed herein may also be used. The sign post 206 includes on thelower end 208 a second component 210 of a breakaway system. The groundscrew anchor foundation 100 is installed such that a majority of thesoil screw 102 is substantially engaged in the soil substrate 212 (alsoreferred to as “soil”, “ground” or “earth”) below the ground surface 214(also referred to as “grade”). For purposes of illustration, the soilsubstrate 212 is shown in the Figures extending only a short distancebelow the grade 214; however, it will be appreciated that the soilactually extends downward a substantial distance past the lower end ofthe soil screw(s).

In preferred embodiments, the soil 212 at the installation site for theroadside sign assembly 200 is unexcavated prior to installation of thesoil screw, i.e., the soil screw 102 may be driven directly intounexcavated soil. Alternatively, the soil screw 102 may be driven intocompacted soil, loose soil, clay, gravel or other ground substrates. Thesecond component 210 of the breakaway system mounted on the lower end208 of the sign post 206 is connected to the first component 116 of thebreakaway system mounted on the upper end 108 of the soil screw 102. Inthis manner, the roadside sign 202 and post 206 are securely supportedby the ground screw anchor foundation 100 to form the roadside signassembly 200.

Referring now to FIG. 3, there is illustrated an enlarged partial viewof a roadside sign assembly 200. For purposes of illustration, the soilscrew 102 is shown “interrupted” such that its overall length (denotedL₃) is not completely shown. In some embodiments, the overall length L₃of the soil screw is within the range from 30 inches to 60 inches. Inpreferred embodiments, the overall length L₃ is within the range from 36inches to 54 inches. In other preferred embodiments, the overall lengthL₃ is within the range from 39 inches to 52 inches. Selection of thelength L₃ for a particular foundation 100 or sign assembly 200 may bedependent on factors such as type of soil substrate and/or size of thesign to be supported. In some embodiments, the overall length L₃ isabout 39.37 inches. In some other embodiments, the overall length L₃ isabout 51.18 inches. The height (denoted H₁) above the top of the soillevel 214 (also called “grade”) of the ground screw anchor foundation100, measured at the upper surface 120 of the first component 116, ispreferably in the range of 4.5 inches to 0.5 inches. In more preferredembodiments, the height H₁ is in the range of 3.9 inches to 4.1 inches.In some embodiments, the height H₁ is about 4 inches.

Referring still to FIG. 3, in preferred embodiments, the first andsecond components 116, 210 of the breakaway system are connected to oneanother in a breakaway manner such that the sign post 206 will shear offthe ground screw anchor foundation 100 if struck by a vehicle that hasleft the road. In the illustrated embodiment, the first component 116comprises a triangular slip base mounted on the ground screw 102, andthe second component 210 comprises a complementary triangular slip base.Each component 116, 210 has a plurality of notches 128 that areconfigured to align with the notches on the counterpart so as to receivea bolt 130 therein. The two components 116, 210 may be secured in abreakaway manner by the bolt 130, nuts 132 and washers 134 as shown inFIG. 3. A bolt keeper plate 136 may be used to hold the bolts 130 inposition during installation.

Referring now to FIG. 4, there is illustrated another embodiment of aground screw anchor foundation for a roadside sign. The ground screwanchor foundation 400 comprises a plurality of spaced-apart soil screwsand a first component of a breakaway system connected to the pluralityof spaced apart soil screws. The ground screw anchor foundation 400 isadapted to provide improved resistance to twisting moments imposed onthe foundation by the sign being supported. Such twisting moments may bemoments (denoted M₁) perpendicular to the longitudinal axis 401 of thesign post 206 (e.g., produced by wind load against the face of the sign)and/or moments (denoted M₂) parallel to the longitudinal axis of thesign post (e.g., produced by the edge of the sign “weather-vaning” intothe wind). For purposes of illustration, only the lower portion of thesign, namely, sign post 206 and second component 210 of the breakawaysystem are shown in FIG. 4.

The ground screw anchor foundation 400 of this embodiment comprises afirst soil screw 402 that may be substantially similar to soil screw 102previously disclosed. The ground screw anchor foundation 400 furthercomprises a second soil screw 404 disposed in a spaced-apart relation ata distance (denoted S₁) to the first soil screw 402. The second soilscrew 404 may be identical to the first soil screw 402, or it may bedifferent. In some embodiments, the second soil screw 404 may have thesame diameters D₁, D₂ and/or D₃ and/or the same lengths L₁, L₂ and/or L₃as the first soil screw 402. The longitudinal axis 104′ of the firstsoil screw 402 is preferably oriented parallel to the longitudinal axis104″ of the second soil screw 404. In preferred embodiments, the soilscrews 402 and 404 are disposed such that a horizontal line 406 betweentheir respective longitudinal axes 104′ and 104″ is oriented parallel tothe direction of travel (denoted by arrow 408). It will be appreciatedthat the face of a roadside sign is typically oriented perpendicular tothe direction of travel 408, therefore, the maximum wind load againstthe face of the sign (for a given wind speed) will occur in thedirection of travel.

Referring still to FIG. 4, and now also to FIGS. 5 a, 5 b, 5 c, 5 d, 5 eand 5 f, the first component 410 of the breakaway system is connected tothe plurality of soil screws 402 and 404. The first component 410includes an elongated channel member 412 defining a lateral axis 413 andhaving a vertical length (denoted L₄), a plate member 418 and asubstantially planar upper surface 420. The plate member 418 is mountedon the channel member 412 so as to position the plate member apredetermined distance (denoted H₂) above the upper surface of thechannel member. In the illustrated embodiment, a stub pipe 422 isconnected between the channel member 412 and the plate member 418 tomount the plate member at the desired height H₂. In preferredembodiments, the height H₂ is 4 inches or less. The channel member 412is preferably installed such that its upper surface is no higher than,or preferably below, the prevailing grade 214. In such installations,only the plate member 418 and any mounting components (such as stub pipe422) will project above the prevailing grade 214.

The plate member 418 may be mounted on the channel member 412 such thatthe plane 424 of the upper surface 420 forms an angle (denoted θ₂) withthe longitudinal axis of the sign post 401 (which will be vertical), theangle being within the range from 60° to 90°. Preferably, the plane 424of the upper surface 420 forms an angle θ₂ within the range from 80° to90°. In some embodiments, the upper surface 420 of the plate member 418is parallel to the upper surface of the channel member 412 (see, e.g.,FIG. 5 d), such that the upper surface of the plate member will behorizontal after level installation of the foundation 400.

In some embodiments (see, e.g., FIGS. 5 a-5 d), the plate member 418 ofthe first component 410 of the breakaway system includes three lateralsides 426 depending from the upper surface 420. The lateral sides 426may be configured in the form of an equilateral triangle (see, e.g.,FIG. 5 b); with each lateral side being configured to terminate beforereaching an apex 428 with an adjacent lateral side, thereby defining anotch 430 at each point of intersection (of the lines extending from thelateral sides). In other embodiments, the plate member 418 may beconfigured as a non-equilateral triangle.

Referring now also to FIGS. 5 e and 5 f, in still other embodiments, theplate member 418 may be configured with its upper surface 420 in theshape of a square, a rectangular or yet another different shape. FIG. 5e illustrates an embodiment of a first component 410 having a platemember 418′ configured in a square shape. FIG. 5 f illustrates anembodiment of a first component 410 having a plate member 418″configured in a rectangular shape. Whether configured as a triangle, asquare, a rectangle or other shape, the plate member 418 of someembodiments may include notches 430 formed at each point of intersectionof the lateral sides (i.e., at the “corners” of the plate member),whereas the plate members of other embodiments may not include notches.

As best seen in FIGS. 5 a and 5 c, the channel member 412 may include apair of side plates 414 connected to either side of a connecting web416. The side plates 414 preferably project from the connecting web 416in the opposite direction from the plate member 418. For example, whenoriented for installation on the ground, the plate member 418 ispositioned above the connecting web 416 and the side plates 414 arepositioned below the plate member. This configuration allows the sideplates 414 to more easily penetrate into the ground to a lower levelthan the connecting web 416 when the foundation is installed.

Referring now to FIG. 6, there is illustrated a roadside sign assemblyin accordance with another embodiment. The roadside sign assembly 600includes a roadside sign 202 mounted on the upper end 204 of a sign post206. A ground screw anchor foundation 400 having multiple soil screws asdisclosed herein is connected to the lower end 208 of the sign post 206.In the embodiment illustrated in FIG. 6, the ground screw anchorfoundation 400 is substantially identical to the foundation described inconnection with FIGS. 4, 5 a, 5 b, 5 c and 5 d, however, other groundscrew anchor foundations as disclosed herein may also be used. The signpost 206 includes a second component 210 of a breakaway system connectedto the lower end 208. The ground screw anchor foundation 400 isinstalled such that the soil screws 402 and 404 are substantiallycompletely engaged in the soil substrate 212 below the ground surface214. The ground screw anchor foundation 400 comprises a plurality ofspaced-apart soil screws 402, 404 and a first component 410 of abreakaway system connected to the plurality of spaced apart soil screws.The roadside sign assembly 600 is adapted to provide improved resistanceto wind loads.

A ground screw anchor foundation for a roadside sign, for example, afoundation 100 according to the embodiment of FIGS. 1 a-1 c or FIG. 3,may be installed in a soil substrate 212 in accordance with thefollowing procedure: 1) providing a first elongated soil screw 102; 2)providing a first component 116 of a breakaway system, the firstcomponent being cooperatively engageable in a breakaway manner to asecond component of a breakaway system adapted for attachment to aroadside sign; 3) connecting the first component 116 of the breakawaysystem to the upper end 108 of the first soil screw 102; 4) releasablyconnecting a torque-supplying device (702, FIG. 7) to the first soilscrew 102; 5) positioning the first soil screw 102 such that the pointsection 112 is disposed on a surface of a soil substrate 212 and thelongitudinal axis 104 is oriented substantially perpendicular to thesurface 214 (i.e., grade) of the soil substrate; 6) rotating the firstsoil screw 102 about its longitudinal axis 104 with the torque supplyingdevice 702 until the helical thread 114 on the point section 112 engagesthe soil substrate 212 and draws the point section a predetermineddistance (e.g., a distance equal to L₃ minus H₁ in FIG. 3) into the soilsubstrate; and 7) disconnecting the torque-supplying device 702 from thefirst soil screw 102. Following this installation of the foundation, asign assembly having a second component 210 of the breakaway system canbe attached to the first component 116.

Connection of the first component 116 to the soil screw 102 is typicallyperformed using a permanent joining method such as welding, brazing,soldering or the like. In some embodiments, however, non-permanentconnection methods such as threading or bolting may be used. Inpreferred embodiments of the installation method just described, thefirst component 116 is connected to the soil screw 102 prior toinstalling the soil screw in the ground; however, this is not required.In some embodiments, the first component 116 may be connected to thesoil screw 102 after installation of the soil screw in the ground.

In some embodiments, the torque-supplying device 702 described hereinmay comprise an electric motor operatively connected to the soil screw102 for rotating the soil screw around its longitudinal axis 104. Inother embodiments, the torque-supplying device 702 may comprise ahydraulic motor or internal combustion engine operatively connected tothe soil screw 102 for rotating the soil screw around its longitudinalaxis 104. In preferred embodiments, the torque-supplying device 702 is ahydraulic- or electric-powered auger attachment mounted on a smallutility vehicle (e.g., a Bobcat® utility vehicle) or utility truck (notshown). However, in other cases the torque-supplying device 702 may be ahand-held (motor-driven) auger drive, or even hand tools such aswrenches equipped with suitable torque-enhancing handles (i.e., “cheaterbars”).

In another embodiment of the installation method, the first component116 of the breakaway system further comprises a plate member 118 mountedon the upper end of the barrel section 106 of the soil screw 102. Inpreferred embodiments, the plate member 118 may have a substantiallyplanar upper surface 120 and three lateral sides 124 depending from theupper surface, the lateral sides being configured in the form of anequilateral triangle. In some such embodiments, each lateral side 124may be configured to terminate before reaching an apex with an adjacentlateral side, thereby defining a notch 128 at each point ofintersection.

Referring now to FIG. 7, in another embodiment, the first component 116of the breakaway system is connected to the soil screw 102 before thesoil screw is releasably connected to the torque-supplying device 702;and the torque-supplying device includes an adapter 700. The adapter 700may be configured to releasably connect to the first component 116 suchthat torque from the torque-supplying device 702 is transmitted throughthe adapter and through the first breakaway mounting member to rotatethe soil screw 102 around its longitudinal axis 104 and into the soil212. The adapter 700 may include a drive plate 704 that is configured tobe releasably connectable to the first component 116 using removablefasteners such as bolts 130 and nuts 132.

A ground screw anchor foundation for a roadside sign, for example, afoundation 400 having multiple soil screws according to the embodimentsshown in FIGS. 4, 5 a-5 d and 6, may be installed in a soil substrate212 in accordance with the following procedure: 1) providing a firstelongated soil screw 402; 2) releasably connecting a torque-supplyingdevice 702 to the first soil screw 402; 3) positioning the first soilscrew 402 such that the point section 112 is disposed on a surface of asoil substrate 212 and the longitudinal axis 104 is orientedsubstantially perpendicular to the surface 214 (i.e., grade) of the soilsubstrate; 4) rotating the first soil screw 402 about its longitudinalaxis 104 with the torque supplying device 702 until the helical thread114 on the point section 112 engages the soil substrate 212 and drawsthe point section a predetermined distance (e.g., a distance equal to L₃plus L₄) into the soil substrate; 5) disconnecting the torque-supplyingdevice 702 from the first soil screw 402; 6) providing a secondelongated soil screw 404; 7) releasably connecting a torque-supplyingdevice 702 to the second soil screw 404; 8) positioning the second soilscrew 404 such that the point section 112 is disposed on the surface 214of the soil substrate 212 and the longitudinal axis 104 is orientedsubstantially perpendicular to the surface of the soil substrate andspaced-apart from the longitudinal axis of the first soil screw; 9)rotating the second soil screw 404 about its longitudinal axis 104 withthe torque supplying device 702 until the helical thread 114 on thepoint section 112 engages the soil substrate 212 and draws the pointsection a predetermined distance into the soil substrate; 10)disconnecting the torque-supplying device 702 from the second soil screw404; 11) providing a first component 410 of a breakaway system, thefirst component being cooperatively engageable in a breakaway manner toa second component of a breakaway system adapted for attachment to aroadside sign; 12) connecting the first component 410 to the upper end108 of the first soil screw 402; and 13) connecting the first component410 to the upper end 108 of the second soil screw 404.

In one embodiment of the method just described, the first component 410of the breakaway system further comprises a channel member 412 connectedto the respective upper ends 108 of the first and second soil screws 402and 404 and a plate member 418 mounted on the channel member. The platemember 418 may have a substantially planar upper surface 420 and threelateral sides 426 depending from the upper surface. The lateral sides426 may be configured in the form of an equilateral triangle; and eachlateral side may be configured to terminate before reaching an apex 428with an adjacent lateral side, thereby defining a notch 430 at eachpoint of intersection.

Although the preferred embodiment has been described in detail, itshould be understood that various changes, substitutions and alterationscan be made therein without departing from the spirit and scope of theinvention as defined by the appended claims.

What is claimed is:
 1. A ground screw anchor foundation for a roadsidesign having a second component of a breakaway system, the ground screwanchor foundation comprising: at least one elongated soil screw defininga longitudinal axis, each soil screw including a barrel section havingan upper end and a lower end defining a first length therebetween, and asubstantially circular cross-section of a first diameter, viewed alongthe longitudinal axis, a point section connected to the lower end of thebarrel section, the point section tapering from a second diameter at aposition along the longitudinal axis proximate to the barrel section toa third diameter at a position along the longitudinal axis distal to thebarrel section; and a helical thread disposed around the longitudinalaxis on an outer surface of at least a portion of the point section; anda first component of a breakaway system mounted on the upper end of thebarrel section of the soil screw, the first component being adapted forreleasable connection in a breakaway manner to a second component on aroadside sign.
 2. A ground screw anchor foundation in accordance withclaim 1, wherein the first component of the breakaway system furthercomprises: a plate member having a substantially planar upper surface;and wherein the plate member is mounted on the upper end of the barrelsection such that the plane of the upper surface forms an angle with thelongitudinal axis, the angle being within the range from 60° to 90°. 3.A ground screw anchor foundation in accordance with claim 2, wherein theplate member of the first component of the breakaway system includes:three lateral sides depending from the upper surface, the lateral sidesbeing configured in the form of an equilateral triangle; and eachlateral side being configured to terminate before reaching an apex withan adjacent lateral side, thereby defining a notch at each point ofintersection.
 4. A ground screw anchor foundation in accordance withclaim 1, further comprising: a second soil screw disposed in aspaced-apart relation to the first soil screw, the longitudinal axis ofthe second soil screw being substantially parallel to the longitudinalaxis of the first soil screw; and wherein the first component of thebreakaway system includes a channel member mounted to the respectiveupper ends of the barrel sections of the first and second soil screwsand a plate member having a substantially planar upper surface mountedon the beam such that the plane of the upper surface of the plate memberforms an angle with the longitudinal axes of the soil screws, the anglebeing within the range from 60° to 90°.
 5. A ground screw anchorfoundation in accordance with claim 4, wherein the plate member of thefirst component of the breakaway system includes: three lateral sidesdepending from the upper surface, the lateral sides being configured inthe form of an equilateral triangle; and each lateral side beingconfigured to terminate before reaching an apex with an adjacent lateralside, thereby defining a notch at each point of intersection.
 6. Amethod for installing a ground screw anchor foundation for a roadsidesign in a soil substrate, the foundation adapted for supporting aroadside sign including a second component of a breakaway system, a signpost attached to an upper side of the second component, and a signattached to the sign post, the method comprising the following steps:providing a first elongated soil screw defining a longitudinal axis, thefirst soil screw including a barrel section having an upper end and alower end defining a first length therebetween, and a substantiallycircular cross-section of a first diameter, viewed along thelongitudinal axis, a point section connected to the lower end of thebarrel section, the point section tapering from a second diameter at aposition along the longitudinal axis proximate to the barrel section toa third diameter at a position along the longitudinal axis distal to thebarrel section; and a helical thread disposed around the longitudinalaxis on an outer surface of at least a portion of the point section; andproviding a first component of a breakaway system, the first componentbeing cooperatively engageable in a breakaway manner to a secondcomponent of a breakaway system adapted for attachment to a roadsidesign; connecting the first component of the breakaway system to theupper end of the barrel section of the first soil screw; releasablyconnecting a torque-supplying device to the first soil screw;positioning the first soil screw such that the point section is disposedon a surface of a soil substrate and the longitudinal axis is orientedsubstantially perpendicular to the surface of the soil substrate;rotating the first soil screw about its longitudinal axis with thetorque supplying device until the helical thread on the point sectionengages the soil substrate and draws the point section a predetermineddistance into the soil substrate; and disconnecting the torque-supplyingdevice from the first soil screw.
 7. A method for installing a groundscrew anchor foundation in accordance with claim 6, wherein the firstcomponent of the breakaway system further comprises: a plate membermounted on the upper end of the barrel section of the soil screw, theplate member having a substantially planar upper surface, three lateralsides depending from the upper surface, the lateral sides beingconfigured in the form of an equilateral triangle; and each lateral sidebeing configured to terminate before reaching an apex with an adjacentlateral side, thereby defining a notch at each point of intersection. 8.A method for installing a ground screw anchor foundation in accordancewith claim 6, wherein: the first component of the breakaway system isconnected to the soil screw before the soil screw is releasablyconnected to the torque-supplying device; and the torque-supplyingdevice includes an adapter, the adapter being configured to releasablyconnect to the first component of the breakaway mounting member suchthat torque from the torque-supplying device is transmitted through theadapter and through the first breakaway mounting member to rotate thesoil screw around its longitudinal axis and into the soil.
 9. A methodfor installing a ground screw anchor foundation in accordance with claim7, wherein the torque-supplying device comprises an electric motoroperatively connected to the soil screw for rotating the soil screwaround its longitudinal axis.
 10. A method for installing a ground screwanchor foundation in accordance with claim 7, wherein thetorque-supplying device comprises a hydraulic motor operativelyconnected to the soil screw for rotating the soil screw around itslongitudinal axis.
 11. A method for installing a ground screw anchorfoundation in accordance with claim 7, wherein the torque-supplyingdevice comprises an internal combustion engine operatively connected tothe soil screw for rotating the soil screw around its longitudinal axis.12. A method for installing a ground screw anchor foundation inaccordance with claim 6, wherein the method further comprises: providinga second elongated soil screw defining a longitudinal axis, the secondsoil screw including a barrel section having an upper end and a lowerend defining a first length therebetween, and a substantially circularcross-section of a first diameter, viewed along the longitudinal axis, apoint section connected to the lower end of the barrel section, thepoint section tapering from a second diameter at a position along thelongitudinal axis proximate to the barrel section to a third diameter ata position along the longitudinal axis distal to the barrel section; anda helical thread disposed around the longitudinal axis on an outersurface of at least a portion of the point section; releasablyconnecting a torque-supplying device to the second soil screw;positioning the second soil screw such that the point section isdisposed on the surface of the soil substrate and the longitudinal axisis oriented substantially perpendicular to the surface of the soilsubstrate; rotating the second soil screw about its longitudinal axiswith the torque supplying device until the helical thread on the pointsection engages the soil substrate and draws the point section apredetermined distance into the soil substrate; disconnecting thetorque-supplying device from the second soil screw; wherein the firstcomponent of the breakaway system is attached to the respective upperends of the first and second soil screws
 13. A method for installing aground screw anchor foundation in accordance with claim 12, wherein thefirst component of the breakaway system further comprises: a channelmember connected to the respective upper ends of the first and secondsoil screws; and a plate member mounted on the channel member, the platemember having a substantially planar upper surface, three lateral sidesdepending from the upper surface, the lateral sides being configured inthe form of an equilateral triangle; and each lateral side beingconfigured to terminate before reaching an apex with an adjacent lateralside, thereby defining a notch at each point of intersection.
 14. Amethod for installing a ground screw anchor foundation in accordancewith claim 12, wherein the first component of the breakaway systemfurther comprises: a channel member connected to the respective upperends of the first and second soil screws; and a plate member mounted onthe channel member, the plate member having a substantially planar uppersurface and being mounted on the beam such that the plane of the uppersurface of the plate member forms an angle with the longitudinal axes ofthe soil screws, the angle being within the range from 60° to 90°.
 15. Aground screw anchor foundation for a roadside sign having a secondcomponent of a breakaway system, the ground screw anchor foundationcomprising: a first elongated soil screw defining a first longitudinalaxis; a second elongated soil screw defining a second longitudinal axis;each soil screw including a barrel section extending along thelongitudinal axis and having an upper end and a lower end defining afirst length therebetween, and a substantially circular cross-section ofa first diameter, viewed along the longitudinal axis, a point sectionconnected to the lower end of the barrel section, the point sectiontapering from a second diameter at a position along the longitudinalaxis proximate to the barrel section to a third diameter at a positionalong the longitudinal axis distal to the barrel section; and a helicalthread disposed around the longitudinal axis on an outer surface of atleast a portion of the point section; an elongated channel memberdefining a lateral axis and mounted to the upper ends of the first andsecond soil screws such that the respective longitudinal axes of thesoil screws are oriented substantially parallel to one another,substantially perpendicular to the lateral axis of the channel memberand spaced apart from one another along the lateral axis; and a platemember having a substantially planar upper surface, the plate memberrigidly connected to an upper surface of the channel member such thatthe planar upper surface is disposed at a predetermined height above thechannel member; wherein the plate member is configured as a firstcomponent of a breakaway system, the first component being adapted forreleasable connection in a breakaway manner to a second component on aroadside sign.
 16. A ground screw anchor foundation in accordance withclaim 15, wherein the channel member further comprises: a connectingweb; a pair of side plates connected to either side of the connectingweb; wherein the side plates project from the connecting web in theopposite direction from the plate member.